The present invention relates generally to the field of implements for farm, ranch, landscaping, and earth moving equipment. More specifically, the present invention relates to the field of implements for a tractor, bulldozer, skid-loader, or any powered vehicle, where the implement is used as a combination rake and grubber. A grubber is a digging tool used for ripping soil and ground cover, cutting unwanted vegetative roots and debris, and dislodging rocks. A rake is a tool used to gather surface and grubbed material into a pile called xe2x80x9crake product.xe2x80x9d
The field related to ripping soil and grubbing is rich with disclosure. Howard (U.S. Pat. No. 2,882,622) discloses a single tool that, when attached behind a bulldozer blade, can be manually moved vertically in a direction perpendicular to the ground to an upper, inoperative position, or to an operative position lower than the blade. When the bulldozer moves forward with the grubber in the lower position, the grubber rips into the ground and, at a preset depth, severs vegetative roots. In a separate subsequent operation with the grubber raised to its inoperative position and the blade lowered to grade level, the bulldozer can scrape or rake the grubbed area.
Harkness (U.S. Pat. No. 4,356,644) discloses a grubber that is mounted on the back of a tractor. The grubber can be hydraulically raised and lowered without need for the operator to dismount the tractor. However, the Harkness grubber requires the operator to back the tractor close to the individual tree or bush to be removed, lower the grubber to the ground, back the tractor further until the grubber blade contacts the roots below the ground, stop the tractor, and then operate the grubber hydraulics to dislodge the roots. Harkness discloses no raking feature.
Price (U.S. Pat. No. 2,491,208) discloses a one-piece multi-toothed rake and grubber combination mounted on the front of a bulldozer or similar vehicle. There is no relative rake and grubber displacement.
Mitchell (U.S. Pat. No. 3,835,932) discloses a combination scarifier and pulverizer for use with earth moving equipment. The scarifier consists of multiple teeth attached to the lower edge of a horizontal transverse member that is removably attached to the bulldozer member arms that support the typical bulldozer earth moving blade. When the vehicle moves forward, the scarifier teeth rip the ground to a depth determined by the adjustable vertical position of the bulldozer blade arms. Plates welded to the scarifier member pulverize the scarified earth as the earth moving vehicle moves forward. The scarified and pulverized material eventually passes between the scarifier teeth and under the pulverizer plates, and no raking function is performed. Although Mitchell provides relative vertical positioning between the scarifier teeth and the pulverizer plates, the teeth must be individually and manually positioned while the vehicle is stopped.
Mann (U.S. Pat. No. 4,407,080) discloses a frame that is hinged to the top of a bulldozer blade. To the frame member parallel to and opposite from the hinged frame member are attached several teeth designed to rip the earth when the hinged frame is deployed in the down position and the bulldozer moves forward. Subsequent to the grubbing procedure, the bulldozer can perform a scraping or raking function by moving in the reverse direction with the blade lowered. During the reverse-motion scraping or raking operation the hinged, toothed frame pivots upward, thus relieving the teeth of potentially destructive forces. The Mann device offers no relative displacement between the row of teeth and the bottom of the bulldozer blade during the ripping operation. The ripping teeth are either deployed in their operative downward position, or pivoted and secured in the nondeployed, upward position. Changing the position of the toothed frame is a manual operation possible only when the bulldozer is stationary.
Applicant enhances the field of implements for farm, ranch, landscaping, and earth moving equipment with his invention of a combination rake and grubber that eliminates the major shortcomings of the currently available implements. Applicant""s invention decreases the time, fuel, and manpower required for clearing land of unwanted rocks, debris, and vegetation. With the disclosed apparatus an operator is able to simultaneously but independently vary the depth of the grubber cut and the height above grade level of the rake. He is able to make such adjustments during the process of clearing land. There is no need to interrupt the work by stopping the work vehicle and dismounting to make a manual adjustment. Such versatility enables the operator to clear land faster than is possible with current grubber implements. Also, the clearing is more precise because the grubber depth and rake height can be varied in response to varying terrain contours, composition, vegetation, and debris.
For example, if in the course of clearing land the operator encounters patches of dense cactus with interspersed mesquite groves, and then encounters a treeless area that must be cleared of debris such as abandoned buried water pipe, he is able to vary the grubber-rake relative position as the job dictates. He does not lose time by stopping work to make equipment adjustments, and he does not have to traverse the same ground twice, once to grub and again to rake.
Every manual operation involving loading, unloading, moving, changing, or adjusting heavy equipment creates potential for fatigue and injury. By decreasing the number of separate implements that must be moved from one work site to another, eliminating the need to manually change between separate grubber and rake implements, and by providing for machine controlled grubber/rake adjustments, Applicant""s invention improves safety.
A combination rake and grubber implement mounted on a work vehicle such as a tractor, skid-loader, or bulldozer has four main members: (1) a lower rake having several fixed or removable teeth that are separated by open spaces or spaces that are partially closed by a solid or porous plate attached to some part of some or all of the teeth; (2) an upper rake that extends generally upward from and is hinged or rigidly attached to the lower rake, is the same or approximately the same width as the lower rake, is solid or porous, and can gather selected rake product according to design, angle of orientation, and porosity; (3) a grubber or set of grubbers attached to the rake or the vehicle so that the grubbers may be deployed, while the vehicle is moving or stationary, anywhere in an arc perpendicular to the rake plane ranging from below the bottom of the rake to above the rake; and (4) a linkage that when actuated, moves the grubbers through their range of motion. During forward motion of the work vehicle the grubbers can cut surface and subsurface roots and debris, unearth rocks, and bring the grubbed product to the surface where it is caught and raked by the rake portions of Applicant""s invention.
Depending on the selected porosity of the toothed, lower portion of the rake, dirt and small pieces of vegetation and rock may flow through the rake or may be caught. As the raked vegetation, debris, and rocks are rolled and piled in front of the rake, the size of product caught by the upper portion of the rake is determined by its design and porosity. For example, Applicant""s rake can be manufactured in a single vertical plane, or it can be made of three vertical planes, the two end planes angled forward so as to better capture rake product by restraining its tendency to roll off the ends of the rake and out of the raked pile.